This invention relates to a threaded fastener assembly and more particularly to a threaded fastener, washer and rubber grommet assembly which is to be preassembled with a first apertured workpiece such as a rocker arm cover which is to be mounted on a second apertured workpiece.
In prior art fastener units such as those shown by the inventions in U.S. Pat. Nos. 4,193,434; 4,292,007 and 4,238,165 the washer is attached to a fastener by means of an annular formation or enlarged section created during a thread rolling operation. It is difficult to form these enlarged sections in a fastener blank at locations other than adjacent to the screw head.
Although, the prior art fastener units provide reliable fasteners the location of the annular formation adjacent to the head of the fastener limits the amount of axial play between the fastener and the washer.
In some instances, significant axial play is required so that the preassembled fastener and first workpiece unit can be placed on a flat surface or second workpiece without the fastener projecting beyond the underside of the first workpiece.
Accordingly, it is an object of this invention to provide a preassembled fastener assembly which provides significant axial play between the fastener and washer.
It is a further object of this invention to provide a fastener assembly which can be preassembled with a first workpiece so that the preassembled unit can be placed on a flat surface or second workpiece without the fastener projecting beyond the underside of the first workpiece.